Samsung stock recovered slightly on Tuesday from the nosedive it took Monday, after U.S. regulators urged consumers to stop using and turn in more than 2.5 million Galaxy Note7 smartphones. Shares closed 4.2 percent higher on Tuesday, erasing some of Monday's $14 billion loss in market value. The Federal Aviation Administration's alert came in response to a small number of incident reports of the Galaxy Note7's lithium ion batteries catching fire, either in transit or while charging on board planes.